This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Staphylococcus sp., a gram positive, non-motile facultative anaerobe, grows over a wide range of temperatures, pH ranges and salt concentrations. Staphylococcus sp. pathogenicity is enhanced by cellular adhesions and extra cellular toxins. One phenomenon observed among isolates is the organism's ability to form a biofilm. Biofilm formation involves intercellular communication resulting in the production of a polysaccharide proteinacious matrix that encapsulates the cell and creates a protective environment. Biofilms greatly inhibit antibiotic effectiveness by providing a barrier to the cell surface proteins and resistance to attack by the human immune response. Quantification of biofilm production isolates was examined in vitro within various environmental conditions. These conditions included 0 [unreadable]10% glucose, 0-10% NaCl, antibiotics, and presence or absence of ethanol in either aerobic or anaerobic environments. Data indicates that coagulase negative Staphylococcus sp. produce more biofilm and are more often associated with serious, prolonged and persistent clinical infections. Multi locus sequence typing and representational differential analysis will be developed to identify differences in gene expression and for molecular speciation.